executing javascript code inside Android "java" application

Question

I'm working on an Android app "native written in java" and I'm getting a response from a server the response is a javascript function

I need to use this function to do some calculations inside my native java code.

any ideas how to do so.

sample response :

function logic_1(surveyString, responseValuesString) { 
    var survey = eval(surveyString);
    var responseValues = eval(responseValuesString);
    var target = new Object();
if (isChosen(128133225, responseValues)) { 
target.id = 2;
}
if (! target.id) { 
    target.id = 2;
 } 
    return target;
 }

Maybe the response could be the result of the function, or a code indicating a java function to run? — Joel, Mar 28 '12 at 09:18
Really suggest to change how the server is responding in case you had access to that. It's a bad habit to return programming-specific data to the client. — SiN, Apr 01 '12 at 21:05

score 3 · Accepted Answer · answered Mar 28 '12 at 09:27

3

I've previously used Rhino successfully to execute JavaScript code on Android: http://www.mozilla.org/rhino/

answered Mar 28 '12 at 09:27

Ian Newson

7,679
2
47
80

I'm getting response as a function that takes 2 input parameters .. can I give this function input from my java code ? I mean "function logic_1(surveyString, responseValuesString)" any way to set those 2 parameters from Java ?? – Helal Ismail Mar 28 '12 at 09:32
Yes, this is not a problem with the Rhino APIs. This answer describes how to do it: http://stackoverflow.com/a/3996115/511012 – Ian Newson Mar 28 '12 at 10:00
works perfect ! thanks okay just another question ... you can see that the function is returning an object var target = new Object(); I was able to catch an integer, boolean, string in the return but how to catch an object ? – Helal Ismail Mar 28 '12 at 12:59
I've posted an example as a separate answer, so I could include code. – Ian Newson Mar 28 '12 at 13:45

score 1 · Answer 2 · answered Mar 28 '12 at 13:45

Here's an example of how to return values from a complex type:

String strFunction = 
        "function add(x,y){ " +
            "return { " +
                "id:x+y " +
            "}; " +
        "}";

Context context = Context.enter();
ScriptableObject scope = context.initStandardObjects();
context.evaluateString(scope, strFunction, "test", 1, null);

Function functionAdd = (Function)scope.get("add");
NativeObject untypedResult = (NativeObject)functionAdd.call(context, scope, scope, new Object[] { 1, 2 });
double id = (Double)untypedResult.get("id", untypedResult);

The important part is the last two lines, where we call the JavaScript function, treat the result as a NativeObject, and then retrieve the value of the 'id' property from that object.

@VivekKumarSrivastava Not specifically, it's for Java using the Mozilla Rhino library: http://www.mozilla.org/rhino/. It will work on Android though. — Ian Newson, Oct 25 '13 at 08:32

antonjs · Answer 3 · 2012-03-28T09:47:22.370

0

Maybe you just need to use a JavaScript auto executing function like this:

(function(x, y){
  var result;
  result = x + y; // do some calculations
  return result;
})(1 , 2); //  you can set your parameters from Java

and 1, 2 are just two parameters from Java

edited Mar 28 '12 at 09:47

answered Mar 28 '12 at 09:25

antonjs

14,060
14
65
91

executing javascript code inside Android "java" application

3 Answers3